Catheters having multiple or segmented balloons mounted thereon are known for a variety of uses. Some of these catheters the balloons communicate with a single inflation lumen, in others the different balloons or segments have separate lumens. Multiple balloons may be mounted on the catheter in tandem, concentrically or asymmetrically.
Certain applications to which catheters are applied present special problems. For instance, carotid artery steno sis has been treated using catheters for coronary angioplasty and/or for peripheral angioplasty, but have characteristic problems that create a need for specifically designed catheters. Carotid artery stenosis often originates in two common vessel areas of treatable significance. Primarily stenosis occurs at the bifurcation of the common carotid artery (CCA) and internal carotid artery (ICA). Secondarily, stenosis occurs in the ICA somewhat distal to the CCA and ICA bifurcation where the vessel size is substantially smaller.
Typically, those lesions found at the bifurcation of the CCA and CA are focal in nature, consist of large amounts of calcium and have a very heterogeneous surface morphology. When treating this kind of lesion set, a physician typically will pre and/or post dilate the lesion with a balloon. The pre-dilatation allows for ease of placement of the stent and the post-dilatation ensures the stent fully apposes the vessel contouring the stent to better conform to vessel configuration so that there is a well defined conduit for increased blood flow. The lesions found at the bifurcation of the CCA and CA make up approximately 80% of the world wide procedures that are treated with carotid artery stents. However, it would be useful if lesions in the internal carotid artery distal to the CCA and ICA bifurcation could also be treated at the same time with the same balloon catheter.
Documents describing some catheter systems and techniques for carotid artery surgery include U.S. Pat. No. 6,086,548 (Chaisson et al); U.S. Pat. No. 6,582,396 (Parodi); and U.S. Pat. No. 6,905,490 (Parodi).